Outcomes of NAFLD and MAFLD: Results from a community-based, prospective cohort study

The Apparent Asymmetrical Relationship Between Small Bowel Bacterial Overgrowth, Endotoxemia, and Liver Steatosis and Fibrosis in Cirrhotic and Non-Cirrhotic Patients: A Single-Center Pilot Study

Introduction

Gut microbiota are a complex ecosystem harboring our intestine. They maintain human body equilibrium, while their derangement, namely, “dysbiosis“, has been associated with several gastrointestinal diseases, such as liver steatosis (NAFLD) and liver cirrhosis. Small intestinal bacterial overgrowth (SIBO) is an example of dysbiosis of the upper gastrointestinal (GI) tract.

Aim

The aim of this study is to evaluate the relationship between SIBO and levels of endotoxemia and grade of liver steatosis (LS) and liver fibrosis (LF) in hepatologic patients.

Materials and Methods

Consecutive outpatients referred to our hepatology clinic were tested for SIBO by the lactulose breath test (LBT) and peripheral blood levels of endotoxemia; LS grading and LF were assessed by abdominal ultrasound and transient elastography, respectively.

Results

Fifty-two consecutive patients (17 with alcohol abuse (4.5 ± 0.8 alcohol units per day), 4 with HCV and 2 with HBV infection, 24 of metabolic origin, 2 of autoimmune origin, and 3 with cholangiopathies; mean age 54.7 ± 8.3 years, 31 F, BMI 24.1 ± 1.1 Kg/m²) and 14 healthy volunteers (HV) (mean age 50.1 ± 4.3 years, 9 F, BMI 23.3 ± 1.1 Kg/m²) were enrolled. SIBO prevalence was significantly higher in cirrhotic (LC) vs. non-cirrhotic (LNC) patients and vs. HV (all, p < 0.05), with a significant positive trend according to Child-Pugh status (all, p < 0.05). SIBO prevalence was not correlated with LS stages (all, p = NS). Consensually, endotoxin levels were significantly higher in LC vs. LNC and vs. HV (all, p < 0.05) and significantly correlated with LF in patients with LC, according to Child-Pugh status (all, p < 0.05).

Conclusion

This study shows that SIBO prevalence and relative endotoxin blood levels seem to be significantly associated with the grade of LF vs. LS in LC. SIBO is also present under pre-cirrhotic conditions, but its prevalence seems to correlate with liver disease irreversible derangement.

Clinical Progression of Metabolic-Associated Fatty Liver Disease Is Rare in a Danish Tertiary Liver Center

Data concerning non-invasive discrimination of simple steatosis from steatohepatitis in metabolic-associated fatty liver disease (MAFLD) and risk of disease progression in patients with MAFLD are conflicting. We aimed to investigate these factors in an MAFLD cohort at a Danish tertiary liver centre. We retrospectively assessed 129 patients with biopsy-proven MAFLD. Patients were divided according to the presence of simple steatosis or steatohepatitis in liver biopsies. Histological and clinical progression were assessed during follow-up. Patients with steatohepatitis had higher BMIs, liver stiffness, HbA1c and soluble (sCD163) and were more prone to have metabolic syndrome at baseline compared with simple steatosis patients. Of the 129 patients, 31 had a follow-up biopsy after a median of 287 days; simple steatosis progressed to steatohepatitis in 7 cases, while 2 regressed. Twenty patients had the same fibrosis stage according to the follow-up biopsy, seven progressed and four regressed. Only 14 patients progressed clinically (median follow-up time was 3.8 years). Clinical progression was associated with female sex, high creatinine, high sCD163 and disease severity in the diagnostic liver biopsy. Steatohepatitis was associated with metabolic and inflammatory parameters including fibroscan. Disease progression was seen in only 11% of cases and was mainly related to more severe histological disease at baseline.

Metabolic Associated Fatty Liver Disease (MAFLD) Increases the Risk of Systemic Complications and Mortality. A Meta-Analysis and Systematic Review of 12,620,736 Individuals

INTRODUCTION

The recent introduction of the definition "metabolic associated fatty liver disease" (MAFLD) sought to reclassify non-alcoholic fatty liver disease (NAFLD). MAFLD is thought to improve the encapsulation of metabolic dysregulation. However, recent evidence has found significant differences between MAFLD and NAFLD and prevailing knowledge has largely arisen from studies in NAFLD. Hence, we conducted a meta-analysis and systematic review on the outcomes associated with MAFLD.

METHODS

Medline and Embase database were searched for articles relating to outcomes in MAFLD. Analysis was conducted in random effects with hazard ratios to account for longitudinal risk assessment of mortality and systemic complications.

RESULTS

A total of 554 articles were identified and a final total of 17 articles were included. MAFLD resulted in an increase of overall mortality (HR 1.24, CI: 1.13 - 1.34), cancer related mortality (HR: 1.27, CI: 1.01 - 1.54) and CVD mortality (HR: 1.28, 1.03 - 1.53, p=0.04) compared to non MAFLD. MAFLD also increases the risk of cardiovascular events (HR: 1.49, CI: 1.34 - 1.64, p<0.01), stroke (HR: 1.55, CI: 1.37 - 1.73, p<0.01) and chronic kidney disease (HR: 1.53, CI: 1.38 - 1.68). The presence of MAFLD was also associated with an increased risk of heart failure, obstructive sleep apnoea and malignancy.

CONCLUSIONS

MAFLD can significantly elevate the risk of systemic diseases and mortality. The care of MAFLD thus requires interdisciplinary collaboration and future clinical trials conducted in MAFLD should aim to reducing the incidence of end organ damage aside from improving liver histology.

Relationship between the dynamics of non-alcoholic fatty liver disease and incident diabetes mellitus

The aim of the current study was to evaluate the association between changes in non-alcoholic fatty liver disease (NAFLD) over time and risk of incident diabetes mellitus (DM). In total, 3047 subjects without underlying DM were followed up for 14 years from the Anseong-Ansan cohort. NAFLD status was determined biennially using the hepatic steatosis index (HSI), and subjects were clustered into seven groups according to changes in HSI, body mass index (BMI), and homeostatic model assessment of insulin resistance (HOMA-IR): none, persistent, transient, transient resolved, resolved, incident, and recurrent NAFLD (Groups 1-7, respectively). Predictive abilities were compared between the dynamics of HSI and single time points. Regarding the changes in HSI, the risk of incident DM was highest in Group 2 (hazard ratio [HR] 2.710; P < 0.001), followed by Groups 7 (HR 2.062; P < 0.001) and 3 (HR 1.559; P = 0.027). The predictive ability for DM was powerful in order of HOMA-IR, HSI and BMI. The dynamics of NAFLD were less predictive of incident DM than single time-point NAFLD. In conclusion, NAFLD is more useful than BMI in predicting incident DM. However, NAFLD status at single time points can better predict incident DM than dynamic changes in HSI.

Systematically comparing epidemiological and clinical features of MAFLD and NAFLD by meta-analysis: Focusing on the non-overlap groups

BACKGROUND & AIMS

The applicability of the novel metabolic dysfunction associated fatty liver disease (MAFLD) definition has been studied in numerous cohorts and compared to non-alcoholic fatty liver disease (NAFLD). No consensus has been reached on which definition is preferred. Therefore, this meta-analysis aims to compare the epidemiological and clinical features of NAFLD and MAFLD in the general and non-general population.

METHODS

We searched Medline, Embase and Web of Science for studies comparing MAFLD to NAFLD. Based on MAFLD and NAFLD status, the following subgroups were investigated for liver health: overlap fatty liver disease (FLD), NAFLD-only and MAFLD-only. Data were pooled using random-effects models.

RESULTS

We included 17 studies comprising 9 808 677 individuals. In the general population, MAFLD was present in 33.0% (95% CI 29.7%-36.5%) and NAFLD in 29.1% (95% CI 27.1%-31.1%). Among those with FLD, 4.0% (95% CI 2.4%-6.4%) did not meet the MAFLD criteria but had NAFLD (NAFLD-only) and 15.1% (95% CI 11.5%-19.5%) was exclusively captured by the novel MAFLD definition (MAFLD-only). Notably, this MAFLD-only group was at significantly increased risk for fibrosis (RR 4.2; 95% CI 1.3-12.9) and had higher alanine aminotransferase (mean difference: 8.0 U/L, 95% CI 2.6-13.5) and aspartate aminotransferase (mean difference: 6.4 U/L, 95% CI 3.0-9.7), compared to NAFLD-only. Similar results were obtained among the non-general population.

CONCLUSIONS

Metabolic dysfunction associated fatty liver disease and NAFLD are highly prevalent in the general population, with considerable overlap between them. However, compared to NAFLD, significantly more individuals were additionally identified by MAFLD than were missed. Importantly, by using the MAFLD criteria, more individuals with liver damage were identified. Therefore, the novel MAFLD definition is superior to NAFLD on a population level.

Metabolic dysfunction-associated fatty liver disease improves detection of high liver stiffness: The Rotterdam Study

BACKGROUND AND AIMS

Recently metabolic dysfunction-associated fatty liver disease (MAFLD) has been introduced and was defined as hepatic steatosis with either overweight, diabetes, and/or a combination of other metabolic risk factors. We investigated the application of the MAFLD criteria as compared with NAFLD.

APPROACH AND RESULTS

We performed a cross-sectional analysis within the Rotterdam Study, a large prospective population-based cohort. Participants who attended the liver ultrasound and transient elastography program between 2009 and 2014 were eligible for inclusion. Subsequently, individuals with viral hepatitis, alcohol intake >60 g/day, missing alcohol data, and/or missing body mass index were excluded. According to their NAFLD and MAFLD status based on metadata and ultrasound, participants were allocated in overlap fatty liver disease (FLD), NAFLD-only, MAFLD-only, or no FLD. Fibrosis was defined as liver stiffness ≥8.0 kPa. In our analysis, 5445 participants were included: 1866 (34.3%) had MAFLD and 1604 (29.5%) [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "1623 (29.8%)"] had NAFLD. This resulted in 1547 (28.4%) [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "1566 (28.8%)"] individuals with overlap FLD, 319 (5.9%) [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "300 (5.5%)"] with MAFLD-only, 57 (1.0%) with NAFLD-only, and 3522 (64.7%) with no FLD. The MAFLD-only group was strongly associated with fibrosis (adjusted OR 5.30 [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "OR 5.27"], p < 0.001) and log-transformed liver stiffness (adjusted beta 0.116, p < 0.001), as opposed to the NAFLD-only group, in which no cases of fibrosis were identified and no association with liver stiffness (adjusted beta 0.006, p = 0.90) was found.

CONCLUSIONS

FLD is highly prevalent in the general population. However, not the NAFLD-only, but the MAFLD-only group was associated with fibrosis and higher liver stiffness-independent of demographic and lifestyle factors. We believe that using the MAFLD criteria will help improve the identification and treatment of patients with FLD at risk for fibrosis.

Impact of renaming NAFLD to MAFLD in an Australian regional cohort: Results from a prospective population-based study

BACKGROUND AND AIMS

Clinical and public health implications of the recent redefining of non-alcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD) remain unclear. We sought to determine the prevalence and compare MAFLD with NAFLD in a well-defined cohort.

METHODS

A cross-sectional study was conducted in regional Victoria with participants from randomly selected households. Demographic and health-related clinical and laboratory data were obtained. Fatty liver was defined as a fatty liver index ≥ 60 with MAFLD defined according to recent international expert consensus.

RESULTS

A total of 722 participants were included. Mean age was 59.3 ± 16 years, and 55.3% were women with a median body mass index of 27.8 kg/m² . Most (75.2%) participants were overweight or obese. MAFLD was present in 341 participants giving an unadjusted prevalence of 47.2% compared with a NAFLD prevalence of 38.7%. Fifty-nine (17.5%) participants met the criteria of MAFLD but not NAFLD. The increased prevalence of MAFLD in this cohort was primarily driven by dual etiology of fatty liver. All participants classified as NAFLD met the new definition of MAFLD. Compared with NAFLD subjects, participants with MAFLD had higher ALT (26.0 [14.0] U/L vs 30.0 [23] U/L, P = 0.024), but there were no differences in non-invasive markers for steatosis or fibrosis.

CONCLUSION

Metabolic-associated fatty liver disease is a highly prevalent condition within this large community cohort. Application of the MAFLD definition increased prevalence of fatty liver disease by including people with dual etiologies of liver disease.

Redefining non-alcoholic fatty liver disease to metabolic associated fatty liver disease: Is this plausible?

Recently, a single letter change has taken the world by storm. A group of experts have developed a consensus to upgrade the term non-alcoholic fatty liver disease (NAFLD) to metabolic associated fatty liver disease (MAFLD), suggesting that MAFLD would more accurately reflect not only the disease pathogenesis but would also help in patient stratification for management with NAFLD. However, the difference of opinion exists, which has made the NAFLD vs MAFLD debate the current talk of the town. This review will focus on the plausibility and implications of redefining NAFLD as MAFLD.

Metabolic dysfunction-associated fatty liver disease and cardiovascular disease: A meta-analysis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease [MAFLD, formerly known as nonalcoholic fatty liver disease (NAFLD)] is one of the most important causes of liver disease worldwide, while cardiovascular disease (CVD) is still one of the main causes of morbidity and mortality worldwide, and the two are closely related. This study aimed to investigate the risk of CVD incidence or CVD-related mortality (CVD mortality) in patients diagnosed with MAFLD under new concepts and new diagnostic criteria.

METHODS

We searched English databases PubMed, Web of Science, Embase, and Cochrane Library for relevant literature. The language was restricted to English.

RESULTS

By 22 January 2022, 556 published studies were obtained through preliminary retrieval, and 10 cohort studies were included in this study. All statistical analyses were performed using Review Manager 5.2 software. Compared with the control group, patients in the MAFLD group had a significantly higher relative risk of CVD incidence or CVD mortality during the follow-up, with an RR rate of 1.95 (95% CI 1.76-2.17, p < 0.01). The incidence of CVD in the MAFLD group was more than twice that in the control group (RR 2.26, 95% CI 2.00-2.54, p < 0.01). The mortality rate of CVD was 1.57 times higher than that in the control group (RR 1.57, 95% CI 1.42-1.72, p < 0.01).

CONCLUSIONS

Patients diagnosed with MAFLD alone had higher cardiovascular mortality than those diagnosed with NAFLD alone based on the available data.

Human Genetics to Identify Therapeutic Targets for NAFLD: Challenges and Opportunities

Non-alcoholic fatty liver disease (NAFLD) is a continuous progression of pathophysiologic stages that is challenging to diagnose due to its inherent heterogeneity and poor standardization across a wide variety of diagnostic measures. NAFLD is heritable, and several loci have been robustly associated with various stages of disease. In the past few years, larger genetic association studies using new methodology have identified novel genes associated with NAFLD, some of which have shown therapeutic promise. This mini-review provides an overview of the heterogeneity in NAFLD phenotypes and diagnostic methods, discusses genetic associations in relation to the specific stages for which they were identified, and offers a perspective on the design of future genetic mapping studies to accelerate therapeutic target identification.

Metabolic-associated fatty liver disease and major adverse cardiac events in patients with chronic coronary syndrome: a matched case-control study

BACKGROUND AND AIMS

A consensus of experts suggests that nonalcoholic fatty liver disease (NAFLD) does not appropriately reflect current knowledge and metabolic-associated fatty liver disease (MAFLD) is supposed to be a more suitable overarching concept. However, the association of MAFLD with cardiovascular outcomes in patients with coronary artery disease has not been examined yet. Thus, this study aimed to assess the impact of MAFLD on major adverse cardiac events (MACEs) in patients with chronic coronary syndrome (CCS).

METHODS

This study included 3306 patients with CCS who were diagnosed with MAFLD. Controls without MAFLD were matched (1:1) to cases by age and gender. All participants were followed up for the occurrence of MACEs. Finally, the association between MAFLD and the risk of MACEs was assessed.

RESULTS

During an average of 55.09 ± 19.92 months follow-up, 376 and 248 MACEs were observed in MAFLD and control groups, respectively. When compared with controls, Kaplan-Meier analysis showed that patients with MAFLD had significantly lower event-free survival rate and multivariate Cox regression analysis further revealed that MAFLD group had significantly increased MACEs risk (both p < 0.05). Stratification analysis suggested that patients with MAFLD overlapped with NAFLD or MAFLD-only had 1.33-fold and 2.32-fold higher risk of MACEs respectively compared with controls (both p < 0.05).

CONCLUSION

This study firstly showed that MAFLD was significantly associated with the risk of MACEs in patients with CCS. Moreover, this relationship remained unchanged irrespective of whether satisfying the NAFLD criteria, providing novel evidence for the good utility of MAFLD criteria in clinical practice.

MAFLD better predicts the progression of atherosclerotic cardiovascular risk than NAFLD: Generalized estimating equation approach

AIM

Metabolic associated fatty liver disease (MAFLD) partly overlaps with non-alcoholic fatty liver disease (NAFLD). Thus, using a generalized estimating equation (GEE) approach, we aimed to investigate the difference in worsening of atherosclerotic cardiovascular disease (ASCVD) risk between patients with MAFLD and NAFLD. We also investigated factors related to the difference between the two groups.

METHODS

We enrolled 2306 subjects with fatty liver (MAFLD 80.7%, NAFLD 63.4%). Subjects with MAFLD/NAFLD were sub-classified into three groups: NAFLD with no metabolic dysfunction (non-Met NAFLD), overlapping, and MAFLD with moderate alcohol consumption (mod-Alc MAFLD). ASCVD risk was estimated by non-invasive tests, including the Suita score. An event was defined as worsening of these scores from the low-risk to the high-risk group. Independent factors for the event were analyzed by Cox regression analysis with the GEE.

RESULTS

In Cox regression analysis, MAFLD (HR 1.08, 95% CI 1.02-1.15, p = 0.014) and alcohol consumption (20-39 g/day; HR 1.73, 95% CI 1.26-2.36, p = 0.001) were independently associated with worsening of the Suita score. In a subanalysis, the incidence of the event was significantly lower in non-Met NAFLD than in the overlapping group (HR 0.70, 95% CI 0.50-0.98, p = 0.042). However, no significant difference was observed in the incidence between the overlapping and mod-Alc MAFLD group (HR 1.19, 95% CI 0.89-1.58, p = 0.235).

CONCLUSIONS

The GEE approach demonstrates that MAFLD better identifies patients with worsening of ASCVD risk than NAFLD. Moreover, the superiority of MAFLD over NAFLD was due to the presence of metabolic dysfunction rather than moderate alcohol consumption.

Transition of an acronym from nonalcoholic fatty liver disease to metabolic dysfunction-associated fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a global public health concern owing to its substantial contribution to chronic liver diseases. The disease is closely linked to metabolic syndrome (MS), suggesting a common biological pathway and shared disease mechanism for both ailments. Previous studies revealed a close relationship of NAFLD with the components of MS including abdominal obesity, dyslipidemia, hypertension, and hyperglycemia. Hence, a group of experts recently renamed NAFLD as metabolic dysfunction-associated fatty liver disease (MAFLD) in order to encompass a more appropriate pathogenesis of the disease. NAFLD was first named to describe a condition similar to alcoholic hepatitis in absence of significant alcohol consumption. However, knowledge pertaining to the etiopathogenesis of the disease has evolved over the past four decades. Recent evidence endorses NAFLD as a terminology of exclusion and suggests that it may often leads to misdiagnosis or inappropriate management of patients, particularly in clinical practice. On the other hand, the new definition is useful in addressing hepatic steatosis with metabolic dysfunction, which ultimately covers most of the patients with such illness. Therefore, it seems to be helpful in improving clinical diagnosis and managing high-risk patients with fatty liver disease. However, it is imperative to validate the new terminology at the population level to ensure a holistic approach to reduce the global burden of this heterogeneous disease condition.

Non-alcoholic fatty liver disease and risk of fatal and non-fatal cardiovascular events: an updated systematic review and meta-analysis

BACKGROUND

Studies have reported a significant association between non-alcoholic fatty liver disease (NAFLD) and increased incidence of cardiovascular disease (CVD). However, the magnitude of the risk and whether this risk changes with the severity of NAFLD remains uncertain. We performed a meta-analysis of observational studies to quantify the magnitude of the association between NAFLD and risk of incident CVD events.

METHODS

We systematically searched PubMed, Scopus, and Web of Science from database inception to July 1, 2021, to identify eligible observational studies examining the risk of incident CVD events amongst adult (age ≥18 years) individuals with and without NAFLD and in which NAFLD was diagnosed by imaging, International Classification of Diseases codes, or liver biopsy. The primary outcomes were CVD death, non-fatal CVD events, or both. Data from selected studies were extracted, and meta-analysis was performed using random-effects models to obtain summary hazard ratios (HRs) with 95% CIs. The quality of the evidence was assessed with the Cochrane risk of bias tool. This study is registered on Open Science Framework, number osf.io/5z7gf.

FINDINGS

We identified 36 longitudinal studies with aggregate data on 5 802 226 middle-aged individuals (mean age 53 years [SD 7]) and 99 668 incident cases of fatal and non-fatal CVD events over a median follow-up of 6·5 years (IQR 5·0-10·2). NAFLD was associated with a moderately increased risk of fatal or non-fatal CVD events (pooled random-effects HR 1·45, 95% CI 1·31-1·61; I²=86·18%). This risk markedly increased across the severity of NAFLD, especially the stage of fibrosis (pooled random-effects HR 2·50, 95% CI 1·68-3·72; I²=73·84%). All risks were independent of age, sex, adiposity measures, diabetes, and other common cardiometabolic risk factors. Sensitivity analyses did not modify these results.

INTERPRETATION

NAFLD is associated with an increased long-term risk of fatal or non-fatal CVD events. CVD risk is further increased with more advanced liver disease, especially with higher fibrosis stage. These results provide evidence that NAFLD might be an independent risk factor for CVD morbidity and mortality.

FUNDING

None.

Dietary Patterns Influence Target Gene Expression through Emerging Epigenetic Mechanisms in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) refers to the pathologic buildup of extra fat in the form of triglycerides in liver cells without excessive alcohol intake. NAFLD became the most common cause of chronic liver disease that is tightly associated with key aspects of metabolic disorders, including insulin resistance, obesity, diabetes, and metabolic syndrome. It is generally accepted that multiple mechanisms and pathways are involved in the pathogenesis of NAFLD. Heredity, sedentary lifestyle, westernized high sugar saturated fat diet, metabolic derangements, and gut microbiota, all may interact on a on genetically susceptible individual to cause the disease initiation and progression. While there is an unquestionable role for gene-diet interaction in the etiopathogenesis of NAFLD, it is increasingly apparent that epigenetic processes can orchestrate many aspects of this interaction and provide additional mechanistic insight. Exciting research demonstrated that epigenetic alterations in chromatin can influence gene expression chiefly at the transcriptional level in response to unbalanced diet, and therefore predispose an individual to NAFLD. Thus, further discoveries into molecular epigenetic mechanisms underlying the link between nutrition and aberrant hepatic gene expression can yield new insights into the pathogenesis of NAFLD, and allow innovative epigenetic-based strategies for its early prevention and targeted therapies. Herein, we outline the current knowledge of the interactive role of a high-fat high-calories diet and gene expression through DNA methylation and histone modifications on the pathogenesis of NAFLD. We also provide perspectives on the advancement of the epigenomics in the field and possible shortcomings and limitations ahead.

Incorporating fatty liver disease in multidisciplinary care and novel clinical trial designs for patients with metabolic diseases

With the global epidemics of obesity and associated conditions, including type 2 diabetes, metabolic dysfunction-associated fatty liver disease, chronic kidney disease, hypertension, stroke, cardiovascular disease, osteoporosis, cancer, and cognitive changes, the prevalence of multimorbidity is rapidly increasing worldwide. In this Review, a panel of international experts from across the spectrum of metabolic diseases come together to identify the challenges and provide perspectives on building a framework for a virtual primary care-driven, patient-centred, multidisciplinary model to deliver holistic care for patients with metabolic dysfunction-associated fatty liver disease and associated metabolic diseases. We focus on clinical care and innovative trial design for metabolic dysfunction-associated fatty liver disease and associated metabolic diseases. This work represents a call to action to promote collaboration and partnerships between stakeholders for improving the lives of people with, or at risk of, metabolic dysfunction-associated fatty liver disease and associated metabolic diseases.

The Chinese Society of Hepatology position statement on the redefinition of fatty liver disease

Fatty liver disease associated with metabolic dysfunction is of increasing concern in mainland China, the world's most populous country. The incidence of fatty liver disease is highest in China, surpassing the incidence in European countries and the USA. An international consensus panel recently published an influential report recommending a novel definition of fatty liver disease associated with metabolic dysfunction. This recommendation includes a switch in name from non-alcoholic fatty liver disease (NAFLD) to metabolic (dysfunction)-associated fatty liver disease (MAFLD) and adoption of a set of positive criteria for disease diagnosis that are independent of alcohol intake or other liver diseases. Given the unique importance of this proposal, the Chinese Society of Hepatology (CSH) invited leading hepatologists and gastroenterologists representing their respective provinces and cities to reach consensus on alternative definitions for fatty liver disease from a national perspective. The CSH endorses the proposed change from NAFLD to MAFLD (supported by 95.45% of participants). We expect that the new definition will result in substantial improvements in health care for patients and advance disease awareness, public health policy, and political, scientific and funding outcomes for MAFLD in China.

NAFLD or MAFLD: Which Has Closer Association With All-Cause and Cause-Specific Mortality?-Results From NHANES III

Background: The recent change of terminology from non-alcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated fatty liver disease (MAFLD) has raised heated discussion. We aim to investigate the association of MAFLD or NAFLD with all-cause and cause-specific mortality to compare the outcomes of the two diagnostic criteria in population-based study.

Methods: We recruited 12,480 participants from the Third National Health and Nutrition Examination Survey (NHANES III) with matched mortality data in 2015. Participants were divided into four groups for survival analysis: without NAFLD or MAFLD, with only NAFLD, only MAFLD. Cox proportional hazard regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality. Subgroup analysis were applied in MAFLD patients.

Results: The weighted prevalence of MAFLD and NAFLD was relatively 27.4 and 27.9%. Participants with NAFLD or MAFLD were largely overlapped (weighted Cohen's kappa coefficient 0.76). MAFLD increased the overall risk for total mortality in a greater magnitude than NAFLD [HR 2.07 (95% CI 1.86, 2.29) vs. 1.47 (1.20, 1.79)], However, the difference was non-significant after metabolic parameters were adjusted. Risks for cardiovascular, neoplasm, and diabetes-related mortality were similar between MAFLD and NAFLD. Referring to individuals without both NAFLD and MAFLD, individuals with only NAFLD showed reduced total mortality [HR 0.48 (0.34, 0.68)] and neoplasm mortality [HR 0.46 (0.24, 0.89)] in crude. Nevertheless, individuals with only MAFLD independently increased the risk for total mortality [adjusted HR 1.47 (1.22, 1.77)] and neoplasm mortality [aHR 1.58 (1.09, 2.28)]. The risk for overall mortality in MAFLD was consistent between subgroups except for race-ethnicity and whether secondary to viral hepatitis.

Conclusions: Participants with MAFLD or NAFLD were highly concordant. MAFLD showed greater risk for all-cause mortality and equal risk for cause-specific mortality referring to NAFLD. The new terminology excluded participants with lower mortality risk and included participants with higher risk. Drug development for MAFLD should consider ethnic differences.

From nonalcoholic fatty liver disease to metabolic-associated fatty liver disease: Big wave or ripple?

There is some dissatisfaction with the term "nonalcoholic fatty liver disease (NAFLD)," which overemphasizes alcohol and underemphasizes the importance of metabolic risk factors in this disease. Recently, a consensus recommended "metabolic (dysfunction)-associated fatty liver disease (MAFLD)" as a more appropriate term to describe fatty liver diseases (FLD) associated with metabolic dysfunction. During the definition change from NAFLD to MAFLD, subjects with FLD and metabolic abnormalities, together with other etiologies of liver diseases such as alcohol, virus, or medication who have been excluded from the NAFLD criteria, were added to the MAFLD criteria, while subjects with FLD but without metabolic abnormality, who have been included in the NAFLD criteria, were excluded from the MAFLD criteria. This means that there is an emphasis on the metabolic dysfunction in MAFLD which may underestimate the prognostic value of hepatic steatosis itself, whereas the MAFLD criteria might better identify subjects who are at a higher risk of hepatic or cardiovascular outcomes. However, non-metabolic risk NAFLD subjects who are excluded from the MAFLD criteria are missed from the diagnosis, and their potential risk can be the cause of future diseases. Although huge controversies remain, this review focused on summarizing recent studies that compared the clinical and prognostic characteristics between subjects with NAFLD and MAFLD.

MAFLD in Obese Children: A Challenging Definition

BACKGROUND

Recently, the new definition of Metabolic (dysfunction) associated fatty liver disease (MAFLD) has gained remarkable scientific interest. We aimed to evaluate the effectiveness of MAFLD definition in selecting obese children at higher cardiovascular risk.

METHODS

A total of 954 obese children and adolescents was retrospectively enrolled. Clinical, biochemical, and metabolic evaluations were performed. Hepatic steatosis was assessed by liver ultrasound. According to the metabolic status, the population was divided in three groups. Group 1 included obese patients without both non-alcoholic fatty liver disease (NAFLD) and metabolic dysregulation; group 2 included patients with obesity and NAFLD (then encompassing one MAFLD criterion); group 3 included patients with obesity, NAFLD and evidence of metabolic dysregulation (then encompassing more than 1 MAFLD criteria).

RESULTS

Patients of Group 3 showed a worse cardiometabolic profile, as also proven by the higher percentage of prediabetes (defined as the presence of impaired fasting glucose or impaired glucose tolerance) compared to other groups (p = 0.001).

CONCLUSIONS

MAFLD criteria in obese children seem to be less accurate in identifying patients having an intrinsic higher cardiometabolic risk. This suggests the need for a more accurate definition in the context of pediatric obesity.